Of all the clashes in tomorrow morning's match between the Stormers and Blues in Cape Town, few are likely to have the impact and velocity of the contest between captains Duane Vermeulen and Jerome Kaino.
Both will start at No8, both are on the verge of celebrating significant milestones, and both have a reputation for hitting like runaway cement trucks.
Vermeulen, 28, will celebrate his 100th Super Rugby match when he leads his team out on to the Newlands ground in Cape Town. For 31-year-old Kaino, it will be his 99th match.
Vermeulen, who made his Springboks debut in 2012, forced himself into the New Zealand rugby public's consciousness last year with his outstanding efforts in the two tests against the All Blacks. It was a wonder how Richie McCaw got to his feet after a Vermeulen hit early in the tight Wellington test won 14-10 by the All Blacks and he was the man of the match in the Boks' 27-25 victory in Johannesburg.
A nominee for the IRB's Player of the Year won by All Black Brodie Retallick, Vermeulen, who began his Super Rugby career at the Cheetahs, comes across as a fairly straightforward character.
"It's the way I was brought up," he told the SA Rugby magazine of his liking for collisions. "There's a line and if someone wants to cross it they have to go through you. I love tackling people but I'm not shy of carrying the ball either. The contact is why we play, otherwise we might as well play chess.
"There are so many good loose forwards in South Africa that you have to be an all-rounder - you have to be able to carry the ball, tackle and poach."
He added of his leadership style: "I never really thought I would be a captain. I'm not a big talker."
The same could probably be said of Kaino's captaincy approach. The Blues No8, awarded the role by coach John Kirwan this year, is also a lead-by-example type.
One of the areas of concern for the Blues last season was their set piece, but they showed enough against the Chiefs at North Harbour in round one that it won't necessarily be a weakness this season. Kirwan also has enough confidence in the likes of prop Angus Ta'avao and locks Hayden Triggs and Josh Bekhuis to keep them in their starting positions for Newlands, with All Blacks Charlie Faumuina and Patrick Tuipulotu set to make an impact from the bench.
"One of the positives we did take from that game was the set piece," Kaino said. "Our lineout was quite sound and the scrum went quite well. We can take a lot of that confidence in against the Stormers who do have a great scrum and hopefully we can dominate in that area."
The 2m tall Bekhuis, a signing from the Highlanders, is a lineout asset but showed against the Chiefs that it's not the only string to his bow. Hooker James Parsons led the defensive effort with 13 tackles (and one miss), with Bekhuis slightly more accurate with 12 tackles and no misses.
As the Stormers look to continue their success after beating the Bulls away in round one, and the Blues go for their first win, the two skippers are on a collision course; Kaino the All Blacks enforcer and Vermeulen, who goes by the nickname "Thor", a battle of two international heavyweights.